Dubuque County John Deere Road Corridor Improvements

Background

Dubuque County sought to reduce accidents, decrease traffic delays, boost freight mobility, and promote expansion along the John Deere Road corridor. The corridor sees a unique blend of large specialty trucks and high peak-hour traffic factors because of its proximity to the John Deere plant in Waterloo. To support construction efforts, the county received a BUILD grant for multimodal improvements.

Approach

Our team worked hand-in-hand with multiple stakeholders to gain NEPA environmental clearance, identify a design alternative that best met the stated goals of the project, and best set up the corridor for future growth and grant requirement coordination. Working with Dubuque County, the City of Dubuque, John Deere, and the Iowa DOT in assessing multiple intersection treatment types, we developed a concept with two single-lane roundabouts. The traffic patterns and truck traffic dictated unique geometric design elements specific to this situation.

Additionally, we designed a new multiuse trail that provided connectivity to the local Heritage Trail system. Primary elements of concern with the trail were impacts to the floodplain and Section 4(f) park land. A Section 404 permit was completed, including HEC-RAS modeling to determine that the final design would not adversely impact the floodplain. The trail features a 50-foot by 10-foot pre-engineered steel truss bridge over a small drainageway. To lower the overall bridge costs and shorten construction time, a unique shallow frost-protected footing was utilized to eliminate typical steel bearing piles.

Results

Final corridor design included two three-leg roundabouts that allow better intersection navigation of oversized vehicles specific to the John Deere plant. Based on extensive modeling and analysis of shift-change traffic patterns at the plant, the roundabouts include a combination of two-lane and single-lane entries, as well as bypass lanes. Multimodal accommodations also provide much-needed bicycle and pedestrian connectivity improvements.